Highly accurate estimation of a three-dimensional center-of-gravity location of a traveling object during travel is advantageous in operation of the traveling object. For example, regarding a container transportation vehicle which transports container cargos imported and exported in international commercial trading, a three-dimensional center-of-gravity location of a container cargo vehicle provides valuable data that directly reflects biased loading of cargos in a container. Therefore, the accurate estimation of the three-dimensional center-of-gravity location can effectively prevent collapse/falling of cargo piles that may take place when a door of the container is opened and unstable traveling of the container transportation vehicle (e.g., unstable traveling on a curved road).
As used herein, the term “biased loading” of the cargos in the container means a deviation of a load point determined by the center-of-gravity of the container cargo in a space depending on a disposition state of the container cargo, and does not mean a deviation of a load point on a flat plane of a bottom surface of the container as generally understood in container transportation business.
There have been proposed a technique for measuring a loaded state of cargos in a vehicle such as a four-wheel truck or a loading abnormality of cargos (see e.g., Patent Literatures 1 to 7). However, in the Patent Literatures 1 to 7, importance of the three-dimensional center-of-gravity location of the traveling object during travel is not recognized. Therefore, consideration should not be given to the Patent Literatures 1 to 7 regarding deriving of the three-dimensional center-of-gravity location.
As a solution to this, the present inventors derived the three-dimensional center-of-gravity location of a vehicle which can be loaded with the cargos and is towed by a towing vehicle, based on a logical dynamic theory and reported this technique (see Patent Literature 8). This can address various social issues caused by the container transportation vehicle.